/*

 * Copyright (c) 2018, Alliance for Open Media. All rights reserved.

 *

 * This source code is subject to the terms of the BSD 2 Clause License and

 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License

 * was not distributed with this source code in the LICENSE file, you can

 * obtain it at www.aomedia.org/license/software. If the Alliance for Open

 * Media Patent License 1.0 was not distributed with this source code in the

 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.

 */

#include <assert.h>

#include <stdlib.h>

#include <math.h>

#include "config/av1_rtcd.h"

#include "av1/encoder/dwt.h"

// Note: block length must be even for this implementation

static void analysis_53_row(int length, tran_low_t *x, tran_low_t *lowpass,

                            tran_low_t *highpass) {

  int n;

  tran_low_t r, *a, *b;

  n = length >> 1;

  b = highpass;

  a = lowpass;

  while (--n) {

    *a++ = (r = *x++) * 2;

    *b++ = *x - ((r + x[1] + 1) >> 1);

    x++;

  }

  *a = (r = *x++) * 2;

  *b = *x - r;

  n = length >> 1;

  b = highpass;

  a = lowpass;

  r = *highpass;

  while (n--) {

    *a++ += (r + (*b) + 1) >> 1;

    r = *b++;

  }

}

static void analysis_53_col(int length, tran_low_t *x, tran_low_t *lowpass,

                            tran_low_t *highpass) {

  int n;

  tran_low_t r, *a, *b;

  n = length >> 1;

  b = highpass;

  a = lowpass;

  while (--n) {

    *a++ = (r = *x++);

    *b++ = (((*x) * 2) - (r + x[1]) + 2) >> 2;

    x++;

  }

  *a = (r = *x++);

  *b = (*x - r + 1) >> 1;

  n = length >> 1;

  b = highpass;

  a = lowpass;

  r = *highpass;

  while (n--) {

    *a++ += (r + (*b) + 1) >> 1;

    r = *b++;

  }

}

static void dyadic_analyze_53_uint8_input(int levels, int width, int height,

                                          const uint8_t *x, int pitch_x,

                                          tran_low_t *c, int pitch_c,

                                          int dwt_scale_bits, int hbd) {

  int lv, i, j, nh, nw, hh = height, hw = width;

  tran_low_t buffer[2 * DWT_MAX_LENGTH];

  if (hbd) {

    const uint16_t *x16 = CONVERT_TO_SHORTPTR(x);

    for (i = 0; i < height; i++) {

      for (j = 0; j < width; j++) {

        c[i * pitch_c + j] = x16[i * pitch_x + j] << dwt_scale_bits;

      }

    }

  } else {

    for (i = 0; i < height; i++) {

      for (j = 0; j < width; j++) {

        c[i * pitch_c + j] = x[i * pitch_x + j] << dwt_scale_bits;

      }

    }

  }

  for (lv = 0; lv < levels; lv++) {

    nh = hh;

    hh = (hh + 1) >> 1;

    nw = hw;

    hw = (hw + 1) >> 1;

    if ((nh < 2) || (nw < 2)) return;

    for (i = 0; i < nh; i++) {

      memcpy(buffer, &c[i * pitch_c], nw * sizeof(tran_low_t));

      analysis_53_row(nw, buffer, &c[i * pitch_c], &c[i * pitch_c] + hw);

    }

    for (j = 0; j < nw; j++) {

      for (i = 0; i < nh; i++) buffer[i + nh] = c[i * pitch_c + j];

      analysis_53_col(nh, buffer + nh, buffer, buffer + hh);

      for (i = 0; i < nh; i++) c[i * pitch_c + j] = buffer[i];

    }

  }

}

void av1_fdwt8x8_uint8_input_c(const uint8_t *input, tran_low_t *output,

                               int stride, int hbd) {

  dyadic_analyze_53_uint8_input(4, 8, 8, input, stride, output, 8, 2, hbd);

}

static int haar_ac_sad(const tran_low_t *output, int bw, int bh, int stride) {

  int acsad = 0;

  for (int r = 0; r < bh; ++r)

    for (int c = 0; c < bw; ++c) {

      if (r >= bh / 2 || c >= bw / 2) acsad += abs(output[r * stride + c]);

    }

  return acsad;

}

static int haar_ac_sad_8x8_uint8_input(const uint8_t *input, int stride,

                                       int hbd) {

  tran_low_t output[64];

  av1_fdwt8x8_uint8_input(input, output, stride, hbd);

  return haar_ac_sad(output, 8, 8, 8);

}

int64_t av1_haar_ac_sad_mxn_uint8_input(const uint8_t *input, int stride,

                                        int hbd, int num_8x8_rows,

                                        int num_8x8_cols) {

  int64_t wavelet_energy = 0;

  for (int r8 = 0; r8 < num_8x8_rows; ++r8) {

    for (int c8 = 0; c8 < num_8x8_cols; ++c8) {

      wavelet_energy += haar_ac_sad_8x8_uint8_input(

          input + c8 * 8 + r8 * 8 * stride, stride, hbd);

    }

  }

  return wavelet_energy;

}